US 3428512 A
Description (OCR text may contain errors)
Feb. 18, 1969 COOPER 3,428,512
MEANS FOR CONVERTING A MANUAL BENCH SEALER TO AN AUTOMATIC SEALER Filed Dec.- 16, 1965 INVENTOR KERM/T H. COOPER 4g} 3 BY 7 2 Z '3 SEALINCLJB 2 J M WIRE 80 ATTORNEY United States Patent 6 Claims This invention relates to heat sealing machines, and more particularly to machines for sealing filled bags made of a plastic material or the like.
In establishments where a relatively small volume of bags in required to be sealed, a so-called bench sealer is sufiicient for their purpose. A bench sealer is one which is supported on a table or other horizontal surface, and each bag must be successively held manually in position during the cycle of operation of the machine and upon completion of the cycle the bag is manually removed and a second bag is held in its place, and so on. The sealing cycle is initiated by closing a main switch, which may be a pedal switch, which the operator closes when he has the bag in proper position and opens after the bag has been scaled.
Such establishments, however, often find it advisable after a time to use an automatic sealer which keeps repeating the cycle without requiring any attention on the part of the operator other than successively feeding in fresh bags as fast as the bags are sealed. This entails considerable expense to the user since at present he must purchase an entirely new and costly automatic machine while the investment in the bench sealer is lost.
It is an object of the present invention to provide means in the form of an attachment for converting a bench sealer to an automatic sealer, thus entailing economic advantages to the owner of the bench sealer since only the attachment need be purchased and attaching it to the bench sealer is extremely simple.
The above as well as additional objects will be clarified in the following description wherein reference numerals refer to like-numbered parts in the accompanying drawing. It is to be noted that it is neither desired nor intended to limit the invention necessarily to any or all of the details shown or described except insofar as they may be deemed essential to the invention.
Referring briefly to the drawing, FIG. 1 is a perspective view illustrating a bench sealer supported on a table.
FIG. 2 is a perspective view illustrating in partly assembled condition and tilted at an angle, a combination unit consisting of the bench sealer structure of FIG. 1 and a second structure which when attached to the bench sealer converts the latter to an automatic sealer.
FIG. 3 is a sectional view taken on the line 33 of FIG. 2 but showing the combination unit assembled.
FIG. 4 is a top plan view of the combination unit, with parts omitted and parts in section.
FIG. 5 is a wiring diagram.
Referring in detail to the drawing, the numeral indicates a manual bench sealer structure which is in the form of a box whose top front edge 11 has a groove 12. A rectangular frame-like member 13, commonly termed a sealing arm, is composed of a shaft 14 shown rotatably mounted in the side walls 15, two opposed sides 16 rigid with the shaft, and a cross-bar 17 which carries a wire 18 adapted to be energized and thus heated when or just before the cross-bar meets the open end of a filled bag 20 manually held in the position shown in phantom in FIG. 1.
An air cylinder 21 whose piston is biased by a spring 21a, FIG. 5, to retract the piston, is mounted against ice the front wall 22 and its piston rod 23 is pivoted to a link 24 clamped about the shaft 14. Thus, upon admittance of compressed air into the cylinder the member 13 is swung downward to engage the heated wire with the open end of the bag in the well known manner. As described below, the member 13 is held in the down position for a predetermined time interval, after which the air is exhausted from the cylinder and member 13 swings back to is uppermost position which may be substantially that shown in the several views. Also mounted within the box 10 are two solenoid-operated air valves 25 and 26, a relay 27, and an electric timer or dwell switch 28, all described below with reference to the wiring diagram.
In FIG. 5 the solenoid which operates air valve 25 is shown at 29 and that which operates air valve 26 is shown at 30. Electric power source terminals are shown at 80. The electric timer device 28 is shown including a motor 79 which upon energization moves a contact finger 31 to the right toward a contact 32 and, upon deenergization, releases the finger to be restored to its original :position in engagement with an arcuate contact 33 by a spring, not shown. Such timers are available on the market, either in the form described or the equivalent to achieve the same purpose, and they have means, not shown, to adjust the time interval during which the motor-driven finger remains in engagement with the arcuate contact 33 while moving toward and finally into engagement with the contact 32, or, in other words, the total time interval during which the motor remains energized. The relay 27 is shown having an armature 35 and two contacts 36 and 37. In FIG. 5 the positions of the relay armature 35 and the timer finger 31 are shown in their original positions in full lines before energization of the relay and motor, respectively, and in broken lines after such energization. The curved broken arrow shown extending from the motor designates the direction in which the motor moves the finger. A switch 50 is closed by the sealing arm when the latter descends to carry the bar 17 and hence the sealing wire 18 down upon the open end of the bag. The sealing cycle is closed by a main switch which may be a pedal switch 38.
A compressed air inlet nipple 39, FIG. 2, communicates via pipe union 40, FIG. 3, through pipe 41 with air valve 25, and via pipe 42 with air valve 26. A pipe or hose 43 communicates With cylinder 21. Air valve 26 has the usual blow-off pipe 43b through which air passes when the valve exhausts, in the usual manner. A normally plugged pipe nipple 44 extends from the base of the blow-off pipe and is exposed outside the wall 22. An electric socket 45 is also mounted in the wall 22, and leads 46, FIG. 5. in a cord 81, FIG. 2, leading from .and in parallel with the main switch 38, are connected to the socket 45 inside the box 10.
The above description applies to a common bench sealer in condition for conversion to an automatic sealer. The bench sealer operates as follows: A filled bag is held by the operator with the open end positioned over the groove 12, as previously set forth. Upon closing the switch 38, current passes from ground through leads 47, 46 and 48 through armature 35, relay contact 37, lead 49 and solenoid 29 to ground, thus causing valve 25 to open and admit air into cylinder 21, whence the sealing arm 13 descends. When the sealing arm has substantially reached its lowermost position the switch 50 is closed, thereby causing current to pass through motor 79 via leads 47, finger 31, contact 33, lead 51, switch 50, leads 52 and 53 to ground. The motor then starts to rotate and move finger 31 clockwise, FIG. 5, over arcuate contact 33. During the preset time it takes for the finger to move off the contact 33 the current also passes through the wire 18 which is shown in parallel with the motor across the switch 50, thus heating the wire and causing the bag sealing step. As soon as finger 31 has left contact 33 it engages contact 32, thus opening the circuit through the wire 18 and motor 79 and sending current via finger 31, contact 32 and lead 54 through relay 27, whence armature 35 swings from contact 37 to contact 36. Thus solenoid 29 is deenergized and spring 21a retracts piston 23 to swing member 13 back into its raised inoperative position, while solenoid 30 is energized via lead 55 to open valve 26 to permit air to pass through the blow-off pipe. The switch 38 is then opened and the sealed bag is manually removed, after which a second bag is held in position to be sealed. The air valve 21 is of a standard construction and exhausts through a vent 43a as is indicated by an arrow in FIG. 5.
The addition or attachment by means of which the above-described bench sealer is converted to an automatic sealer, is indicated by the numeral 56, It consists of a box-like structure having the same width and height as the structure and preferably having greater length; it includes an outer end wall 57, side walls 58, and the top wall 59 as well as a bottom wall; the inner end of the structure is preferably left unwalled, or open. In order that the two structures 10 and 56 may be properly aligned with each other and to maintain rigidity of the combined unit, the structure 56 is provided with rails 60, preferably angle-shaped, on which the structure 10 rests and may be slid. With the two structures joined end-toend, plates 62 are screwed to the walls of the structure 10, preferably after drilling holes 61 in the said walls. The combined unit thus formed is used by mounting it on a horizontal surface with the structure 10 uppermost, at an angle of tilt suflicient to exceed the angle of repose of a filled bag resting on the structure 56. The unit may be supported in the tilted position by any means or in any suitable manner. Such means may be, by way of example, a block, a small bench, a table or the like shown in phantom at 63 in FIG. 2.
The top wall 59 of the structure 56 is shown having a plurality of longitudinal slots '64 and a median or center slot 65 therein. The side walls have co-planar longitudinal slots 66 therein. A transverse support member 67 is slidably mounted in the slots 66 and is releasably locked in the desired longitudinal position by set screws 68. At tached to the bottom of the support 67 is an air cylinder 82 whose piston rod 69 extends downward and is normally restored to uppermost position by a spring 70. Such cylinders are of standard construction and are provided with the usual exhaust vent, not shown. Secured to the rod 69 is an arm 71 of a transverse panel or carriage 72 having pins 73 extending upward and riding in the slots 64. A micro-switch 75 which, as described below, serves as a cycle switch for automatic continuous repetitive operation of the combined unit 10, 56 is shown mounted midway on the support 67 with its arcuate cam-like actuating finger or button 74 normally urged by a spring, not shown, upward through the central slot 65. Leads 76 from this switch terminate in a plug 77 which is plugged into the socket 45 in the front wall 22 of the structure 10. An air hose 78 leading from the cylinder 82 is coupled to the nipple 44 after unplugging the latter, of the structure 10. Thus, when air flows through this hose into cylinder 82 its piston 69 and hence carriage 72 is depressed to retract the pins 73 below the top surface of the wall 59.
For automatic operation of the combined unit 10, 56 in the tilted position, pedal switch is not used and it remains Open. FIG. 5 shows, however, that switch 75 is in parallel with the pedal switch. The longitudinal position of the support 67 is adjusted in an obvious manner according to the length of the bag so that the closed end of the bag rests against the normally upstanding pins 73 and the open mouth of the bag lies over the shoulder 12 of the structure 10. The weight of a filled bag so positioned depresses the switch arm 74, thus starting the sealing cycle which continues through the same steps as previously described opon closing pedal switch 38, which cycle terminated in opening the blow-0E valve 26. Now, however, since air from the open valve 26 also passes simultaneously through hose 78 into cylinder 82, the arm 71 is pushed down and thus the pins 73 are retracted whence the sealed bag immediately slides down the wall 59. As soon as the bag has slid clear of the switch the new enlarged cycle terminates since the switch 75 now serves as the main switch, whence it may be termed a cycle switch, and the pins are restored to their upstanding position since the air supply to valve 26 is cut off as soon as the switch 75 again opens. Thus, all an operator need do is to lay a new bag in position for sealing each time a sealed bag has slid down the device, since a new cycle is initiated every time a filled bag is laid in position.
FIG. 1 shows in a side wall thereof an air nipple 83 to which a hose, not shown, from the source of compressed air is connected, and an electric socket 84 to which a plug, not shown, from a lead connected to the power supply terminals, is attached. A rheostat 85 is shown in FIG. 5 in series with the sealing wire 18 to control the degree of heating of the wire.
In most cases sealers are designed to operate on alternating current, in which case a transformer, not shown, is incorporated in an obvious manner to reduce the voltage or to supply the same or different voltages to different parts of the circuit, Basically, however, the wiring diagram and the above description illustrates the manner of operating of a bench sealer per se and the combination automatic unit,
1. Means for converting to an automatic heat sealer a bench heat sealer structure for sealing filled bags or the like wherein said bench structure has means operable upon closing a main switch for initiating and maintaining for a predetermined interval of time a cycle consisting of the sequential steps of pressing an enengized heated wire against the open end of a manually held filled bag, releasing the wire from the bag and deenergizing the wire, said first-named means consisting of a second structure having means for securing the same to said bench structure with the top surfaces of both said structures lying in a common plane, the combination unit thus formed by both said structures being adapted to be supported 'with said bench structure uppermost on a horizontal surface at an angle greater than the angle of repose of a filled bag situated thereon, said second structure having longitudinally adjustable normally upwardly projectimg stop means thereon and being adapted to have the filled bag laid thereon with said open end of the bag positioned for application of said energized wire thereto as aforesaid and with the opposite end of the bag engaged by said stop means whereby the stop means prevents the bag from sliding down said second structure, said second structure having a normally open micro-switch projecting above the top surface thereof in the bag-receiving area thereof, said micro-switch being connected in parallel with said main switch and being closed by the weight of the filled bag and serving as a substitute for said main switch to initiate and maintain said cycle, means maintaining said stop rrneans in the normal upwardly projecting position, means for retracting said stop means, and means for actuating said retracting means upon completion of said cycle.
2. Means for converting to an automatic heat sealer a bench heat sealer structure for sealing filled bags or the like wherein said bench structure includes a main switch and means operable by closing said switch for initiating and maintaining for a predetermined time interval a cycle consisting of the sequential steps of pressing an energized heated wire down against the open end of a filled bag manually held against the front top edge of the structure, releasing the pressure on the bag and deenergizing the wire and finally passing air through a pipe provided with a blow-off nipple to blow away the waste balg material whence the sealed bag is manually removed,
said first-named means consisting of a second structure and means for securing the same end-to-end to said bench structure with the tops of both said structures lying in a common plane, the combination unit thus formed by both said structures being adapted to be supported on a horizontal surface with said bench structure uppermost at an angle greater than the angle of repose of the filled bag on said second structure, said second structure having longitudinally adjustable transversely arranged projecting means normally projecting above the top thereof and being adapted to have the filled bag laid thereon with said open end thereof positioned for application of said wire thereto as aforesaid and with the opposite end of the bag engaged by said projecting means thereby normally stopping the bag from sliding down said second structure, said second structure having a normally open micro-switch connected in parallel with said main switch and projecting above said top thereof in the bag receiving area thereof, said micro-switch being depressed by the weight of said filled bag and serving as a substitute for said main switch to initiate and maintain said cycle, and means connected with and operable simultaneously by said blow-off pipe for retracting said upwardly projecting means to permit the sealed bag to slide down and said micro-switch to return to normal open position.
3. A means for converting a bench sealed according to claim 2, wherein said top of said second structure has a plurality of longitudinal slots therein, said projecting means comprising pins slidably mounted in said slots.
4. A means for converting a bench sealer according to claim 3, wherein a transverse member is longitudinally slidably mounted in said second structure, an air cylinder being secured to the underside of said member and provided with a piston and piston rod normally biased to project the piston rod downward, a vertical carriage adjacent said air cylinder having means securing the same to said rod, said pins being mounted on said carriage, said air cylinder having a hose connecting the same with said blow-off pipe to force said piston and rod and hence said carriage and said pins downward upon actuation of said air cylinder by entry of air thereinto through said hose.
5. A [means for converting a bench sealer according to claim 4, wherein said top of said second structure has an additional longitudinal slot positioned substantially midway of the width thereof, said micro-switch being mounted on said transverse member and projecting upward through said additional slot.
6. A means for converting a bench sealer according to claim 5, wherein said structure of the bench sealer has a front wall under said top front edge thereof, said front wall having a nipple extending therethrough and having an electric socket therein, said blow-off pipe having a branch pipe connected to said nipple inside the bench structure, leads connecting said main switch to said socket, said air hose being coupled to said last-named nipple, leads connected at one end to said micro-switch and having an electric plug at the other end thereof, said plugs being engaged in said socket.
References Cited UNITED STATES PATENTS 3,012,387 12/1961 Jacobs et al. S376 3,214,317 10/1965 Rucker et al 1565'15 3,284,987 11/1966 Sigmon 5376 X EARL M. BERGERT, Primary Examiner.
T. R. SAVOIE, Assistant Examiner.
US. Cl. X.R. 156-583; 5376